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

Annotations already declare the safety profile (readOnlyHint=true, openWorldHint=false, destructiveHint=false), so the description is free to add the non-obvious detail that the text block duplicates the JSON as a string. That quirk is genuinely useful invocation context, though nothing is said about missing ids, errors, or truncation.

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 front-loaded sentence names the resource and enumerates the returned fields; the second short sentence carries the JSON-string quirk. No filler, nothing repeated from the schema.

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 an output schema present, the description need not document return values, and annotations cover the safety profile; the remaining need is minimal for a one-parameter read. Only the absence of any failure-mode or rate-limit note keeps it from being fully complete.

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?

Only one parameter, and schema description coverage is 100% ('An id from a search result'), so the schema already carries the semantics. The description restates the same idea without adding format, length, or validity details beyond the schema's maxLength.

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 (fetch) and resource (one knowledge record) and pins the identifier's provenance to 'the id a search result gave,' which implicitly positions it as the follow-up to a search. It never names a sibling tool, so the differentiation from get_by_name, get_entity, or object_page is left for the agent to infer.

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 precondition is stated clearly: the id must come from a search result, which tells the agent to call this after a search rather than as a standalone lookup. There is no explicit when-not guidance or named alternative for lookups by name or entity.

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