mcp_engram_evolution_at_locus

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

With no annotations, the description carries the transparency burden. It discloses auto-ingest as a side effect (modifying the store) and notes safety via bounded stem prefix. However, it does not explicitly state that auto-ingest is a write operation, nor does it mention potential costs or irreversibility.

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 a single, focused paragraph that front-loads the purpose and return fields. It is concise without being terse, though it could be slightly more structured (e.g., bullets) for easier parsing. No wasted sentences.

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?

The description explains return fields (no output schema) and auto-ingest behavior. With 6 parameters, it covers the key functionality: spatial filtering (implied by 'in range'), trace depth, preview chars. The mention of 'bounded evolution bundle' gives context. Lacks detailed explanation of spatial filter interplay, but overall complete.

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?

Schema description coverage is 100%, so parameters are already documented. The description adds no extra details about parameters themselves (e.g., how line_start/line_end affect spatial filtering), but it does describe output fields that depend on parameters. Baseline 3 is appropriate.

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 it returns an 'evolution bundle at a file locus' and enumerates specific return fields (loci, arcs, trace_chain, etc.). It distinguishes itself from siblings like context_for_edit by mentioning auto-ingest behavior and same resolution, making its purpose specific and unique.

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 implies usage when needing spatial evolution data at a file locus and auto-ingests when no loci exist. It mentions safety on large stores, but does not explicitly state when to use this tool versus alternatives like context_for_edit or force_spatial_ingest. More explicit guidance would improve this.

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