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

Annotations already declare readOnly/idempotent/non-destructive/open-world, yet the description adds substantial context: trial expiry behavior, fields to verify in the response (trialEndsAt, data as-of date, review hold, missing values), the nature of export figures as HS/region-linked estimates rather than disclosed amounts, prompt-injection caution, and explicit exclusions of member info/memos/report originals.

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?

Dense but front-loaded: trial context first, then action semantics, then response caveats and data-handling warnings. Every sentence earns its place, though the block runs long with several caveats packed together.

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 no output schema, the description compensates by telling the agent what to inspect in the response (trialEndsAt, data date, review hold, missing values) and by warning about estimate semantics and excluded data. Complete enough for a 3-param, no-output-schema tool.

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 carry the burden, and it does: each action enum value is defined, and ticker (6 digits) and months (1~24) are scoped to company_exports. The months default of 15 is left to the schema, which is a minor omission.

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 and resource (reading KED's real data without login during the trial) and enumerates the three actions with distinct meanings. An agent can distinguish rerating_candidates, rerating_exports, and company_exports from the description alone, and none of the unrelated sibling tools overlap.

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?

Explains the trial context and the transition condition (paid membership + /mcp/private after expiry), and the action definitions effectively guide which action to select. It stops short of explicit when-not-to-use guidance, but the siblings are unrelated enough that this is not a material gap.

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