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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so safety behavior is covered. The description adds one genuine piece of context not in the annotations: only 'public' documents are retrievable. It says nothing about error behavior for missing/non-public IDs, but with annotations doing the heavy lifting a 3 is appropriate.

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?

One short sentence with no filler, and the key constraint (single document, by ID) is front-loaded. It is efficient, though too terse to earn a 5.

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 single-parameter read tool with rich annotations and no output schema, the description covers the essentials. Only the public-vs-private access limitation and retrieval source are touched on; no return-format detail is needed given no output schema exists.

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%, so the schema documents only type and length bounds. The description adds the meaning of the single parameter ('its ID' identifies the document), but no format, source, or validity detail. For a single self-evident identifier parameter, this is minimally adequate.

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 (read), resource (evidence document), and scoping condition (by its ID, one document). This is clear enough to distinguish from listing/searching siblings like evidence_search or evidence_benchmarks, though it does not name an alternative explicitly.

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?

There is no explicit when-to-use guidance or routing to alternatives. The phrase 'by its ID' weakly implies the caller must already hold an ID, but nothing states when to use this versus evidence_search or evidence_universal_search.

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