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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered structurally. The description adds that results are grouped by topic and oriented toward differences, which is useful framing. It does not need to explain return values since an output schema exists, so this is adequate but not rich.

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 tight sentences with the purpose front-loaded and the default behaviour placed last, which is the right ordering. The illustrative clause 'for example on authentication or on what a submission needs' is slightly padded but earns its place by concretizing 'topic'.

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 100% schema coverage, full annotations, an output schema, and no required parameters, the description carries only what the structured fields cannot: the comparative intent and the grouped output. Nothing essential for calling the tool is missing, though the category parameter's narrowing effect goes unexplained.

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 100%, so both parameters are already documented, including the default platform set. The sentence about omitting platforms restates the schema default and the description never clarifies that 'category' narrows the comparison to a single topic, so it adds little beyond the schema baseline.

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 gives a specific verb (compare/sets side by side) and resource (platform requirements), plus the output shape ('grouped by topic... to show where they differ'). It implicitly separates itself from single-platform siblings like get_platform_requirements, but never names an alternative explicitly, so it stops short of a 5.

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?

'Leave platforms out to compare all four directories' documents the default invocation, which is real usage guidance. However, there is no statement of when to prefer this over get_platform_requirements or get_requirement, and no caveats about when comparison is not appropriate.

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