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

Annotations already establish read-only, idempotent, open-world, and non-destructive behavior. The description adds useful behavioral context beyond that by noting that missing results and definition mismatches are not surfaced, and that comparisons are against 'frozen' forecasts. This helps set expectations without contradicting the annotations.

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 concise: four short sentences, with the core action front-loaded. Each sentence adds a meaningful constraint or clarification, and there is no filler or repetition of structured fields.

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?

Output schema existence reduces the need to describe return values, and annotations cover safety semantics. However, for a three-parameter tool with zero schema descriptions, the lack of revision-parameter semantics is a significant gap. An agent would likely struggle to know how to populate forecast_revision and actual_revision correctly.

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 description must compensate, but it does not define what 'forecast_revision' or 'actual_revision' mean, how they relate to frozen forecasts, or what a null actual_revision implies. The high-level purpose is clear, but the revision parameters are left underspecified.

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 clearly states a specific action and resource: 'Compare frozen revenue forecasts with reported results.' It is not a tautology and gives a distinct purpose from the general sibling tools, though it does not explicitly differentiate itself from closely named siblings like compare_company_revisions.

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?

It provides useful context for when the tool is valid ('Forecasts must precede quarter end') and what limitations exist ('Missing results and definition mismatches remain unavailable'). However, it does not name alternative tools or give explicit when-to-use versus when-not-to-use guidance beyond the vague 'This is not market-memory calibration.'

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