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Record a Catch (append to defect memory)

lens_catches_add

Record a discovered defect, its pattern, and the prevention rule to the defect bank so future work catches the same mistake.

Instructions

Append a NAMED DEFECT to the defect bank so it is caught next time. Record what was WRONG, the general pattern it is an instance of, and the forward rule that prevents it — doctrine REJECTS routine passes, so only log actual defects. Set self_catch=true when the defect was a failure of your own validation discipline. This is the write half of the improvement loop: enough recurrences of a pattern promote it to a deterministic check.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
cwdNoWorking directory to run in. catches.jsonl is read from and written to here. Defaults to the server's cwd.
ruleYesThe forward rule that prevents this next time
catchYesWhat was WRONG (the specific defect found)
domainYesDomain, e.g. marketing, finance, agency
patternYesThe general trap this is an instance of
self_catchNoTrue if this was a failure of the validator's own discipline
artifact_typeYesArtifact type, e.g. landing-copy, research-brief

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. First observedv1.1.1

TDQS

A4.4/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the transparency burden. It discloses that the operation appends to a defect bank, that routine passes are rejected, that self_catch has a specific meaning around validator discipline, and that repeated patterns can promote to deterministic checks. It does not state output/return behavior or error handling, but for an append operation the core side effect is clearly conveyed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three dense sentences with no filler. The core action is front-loaded, policy guidance follows immediately, and the final sentence provides useful context about the improvement loop. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers purpose, policy, self-catch semantics, and the improvement-loop context. It is missing only an explicit pointer to the read-half siblings and any description of what the agent should expect after a successful append, but given 100% schema coverage and the simplicity of the operation, the remaining gaps are minor.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description adds real semantic value beyond the schema by explaining that self_catch=true means a failure of the validator's own discipline and by connecting catch, pattern, and rule to the intended defect-recording workflow. It does not add much for artifact_type or domain, but those are already self-explanatory in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Append a NAMED DEFECT to the defect bank so it is caught next time.' It clearly differentiates itself as the write half of the improvement loop, which distinguishes it from read-oriented siblings like lens_catches_relevant and lens_catches_stats.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear usage context: use this when an actual defect is found, and explicitly warns not to log routine passes ('doctrine REJECTS routine passes'). It frames the tool as the write counterpart to the loop, but it does not explicitly name read alternatives or spell out conditions for when to use sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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