Recall a Fact

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

Annotations already cover read-only, idempotent, and closed-world behavior. The description adds meaningful context beyond that: it retrieves facts stored in a previous session and performs exact matching only — a behavioral constraint that prevents an agent from expecting fuzzy results. It doesn't discuss auth or rate limits, but none are implied.

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?

Two short sentences, front-loaded with the core action and immediately followed by the key constraint. Every word earns its place; no filler or repetition.

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 single-parameter read tool, the description, schema, and annotations together cover all an agent needs: what it does, how to call it, the exact-match constraint, the return behavior (via schema), and the safety profile (via annotations). 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 coverage is 100%, and the schema already documents that the id must be the exact id from a previous remember call, including the possible 'no memory for <id>' response. The description's 'by id' and 'exact lookup' reinforce but do not add syntax or format details beyond what the schema provides, so the 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?

States a specific verb (Retrieve) and resource (a fact stored in a previous session), scoped by id. The phrase 'Exact lookup — not fuzzy or substring' clearly distinguishes it from broader search or fuzzy-match operations, and the verb contrasts naturally with siblings like remember and forget.

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?

Provides clear context: use when you have an id from a previous remember call, and explicitly excludes fuzzy/substring lookups. However, it does not name alternative tools or describe when to prefer remember/forget/list operations, so it stops short of full when/when-not/alternatives guidance.

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