kb_at

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states that the tool is read-only, an important safety trait, and describes the error behavior for unknown IDs (returns {error: not_found}). It also discloses the returned fields, giving a clear picture of the operation's outcome.

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 compact and front-loaded with the core purpose. The two sentences cover purpose, data source, returned fields, error behavior, read-only nature, and relationship to a sibling tool. No wasted words; every sentence contributes 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?

For a simple fetch tool with no annotations and no output schema, the description provides key contextual details: purpose, data source, return content, error case, and read-only status. The only notable omission is the meaning of the app_id parameter, which prevents a perfect score. Overall, it is adequately complete for an agent to use the tool correctly in most cases.

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?

The schema has 0% description coverage for its two parameters, and the description only clarifies the role of atom_id ('by its exact ID'). It does not explain what app_id is for, leaving a gap in understanding a required parameter. This is a significant shortfall for a simple tool with only two parameters.

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 uses a specific verb ('Fetch') and resource ('one knowledge-base atom'), specifies the data source ('fleet Postgres'), and lists the returned fields (content, domain, source, tags). It also distinguishes itself from the sibling tool knowledge_search by calling itself the 'direct-address companion.' This is a clear, non-tautological statement of purpose.

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 frames the tool as 'the direct-address companion to knowledge_search,' indicating that this tool is for fetching by exact ID while knowledge_search is for searching. This gives the agent clear guidance on when to use this tool versus an alternative.

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