search_messages

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

No annotations are present, so the description bears full responsibility. It reveals that messages are cached, implying a non-live data source, but does not mention read-only nature, case sensitivity, result shape, or staleness implications.

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?

A single five-word sentence that efficiently packs the operation, qualifier, and resource. No filler or redundancy; every word contributes semantic value.

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?

With no output schema and no annotations, the description omits return format, cache-specific caveats, and any comparison to list_messages. An agent can guess the basic call, but cannot fully judge expectations around result scope or freshness.

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 0% and the schema only provides types and constraints. The phrase 'substring search' clarifies that the query parameter is the substring, adding meaning beyond the schema. However, the limit parameter's role is left to inference from its name and schema defaults.

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?

Description uses a specific verb 'search' with resource 'cached messages' and the qualifier 'substring', making the operation unambiguous. It also distinguishes itself from siblings like list_messages by emphasizing substring matching.

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?

No guidance on when to use this tool versus alternatives such as list_messages. The description states what it does but not the context in which it should be preferred, missing exclusions or routing hints.

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