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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds substantial context beyond this: case-insensitive substring matching, per-hit field-match reporting, up to 3 body snippets with blockId correspondence to get_mnemon, visibility scoping, and limit/hasMore behavior. No contradictions with annotations exist.

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 four sentences, front-loaded with purpose, followed by usage guidance, then output details. Every sentence adds value: case-insensitive behavior, sibling distinction, hit reporting, snippet targeting, visibility, and pagination. No fluff or redundancy; exceptionally well-structured.

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 tool's complexity, an output schema exists, and annotations are provided, the description covers all necessary contextual grounds: what is searched, how results are structured (field matches and snippets), how to use snippets for subsequent updates, user visibility constraints, and pagination. Nothing critical is missing.

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 the baseline is 3. The description adds minimal parameter-level detail beyond the schema; it restates limit defaults and query semantics already present in the schema. However, it does clarify the blockId relationship for the query parameter's output, which slightly enriches context, but not enough to push above baseline.

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 opens with a specific verb and resource: 'Full-text search across mnemon titles, tags, and body content' with case-insensitive substring semantics. It clearly distinguishes from the sibling tool list_mnemons by stating when search_mnemons is preferred, making its purpose unmistakable.

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?

Explicit guidance is provided: 'Prefer this over list_mnemons when looking for entries by what they contain' names the alternative and gives a concrete example query. It also implies when not to use it (when listing all mnemons is the goal), satisfying the when-to-use vs. alternatives criterion.

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