ism_coverage_upsert

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

The description goes far beyond the annotation hints (idempotentHint, destructiveHint). It discloses atomic rewrite, whole replacement of existing entries, validation against ISM DB, requirement for attachment paths to exist on disk, default value for last_reviewed, and return of action taken plus warnings/failures. No contradiction with annotations.

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

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

The description is concise but packs substantial information. It front-loads the core purpose in the first sentence, then adds critical context in subsequent sentences. Every sentence earns its place, with no redundancy or filler.

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

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

Given the complexity (12 parameters, 3 required, no schema descriptions, and existence of an output schema), the description covers the core behavior, validation rules, and return value. It could mention the output schema or explain more optional parameters, but it provides enough for an agent to use the tool correctly.

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

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

With 0% schema description coverage, the description compensates well by explaining the 'status' enum values, the default for 'last_reviewed', validation rules for identifiers and attachments, and that URLs/attachments need descriptions. However, not all 12 parameters are individually described, leaving some like 'files', 'commits', 'reviewed_by' unaddressed.

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

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

The description clearly states the tool creates or updates one entry in the coverage manifest, specifying the exact resource (.ism-coverage.toml) and using the verb 'upsert'. It explicitly distinguishes from siblings by stating it is 'the only tool that writes to disk'.

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

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

The description explicitly states when to use the tool: for writes to the coverage manifest, and that it is the only write tool, effectively excluding all sibling read-only tools. It also lists conditions for proper use (valid identifier, attachments on disk, URLs/attachments with descriptions) and failure modes (validation errors).

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