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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds useful context beyond annotations: the GET endpoint, the $0.25 cost, the forecasting nature of the result, and filter behavior such as cpv prefix matching. It does not describe output format or pagination, but the annotations lower the burden.

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 a single compact sentence that front-loads the endpoint and cost, states the purpose, and packs the relevant filters and defaults. No words are wasted, and every clause adds useful information.

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 tool with eight optional parameters, no required parameters, and no output schema, the description covers the core forecast purpose, key filters, defaults, and cost. It does not explain the response payload or how this differs from research/search tools, but the schema and annotations fill most of the remaining invocation gaps.

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 low at 25%, so the description needed to compensate. It explains that cpv is a prefix, identifies which parameters act as filters, and states defaults for window_months and min_confidence. However, it omits page, size, and payment-related parameters, and for buyer it only repeats the parameter name.

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 names a specific operation—forecasting signals for likely re-tenders—and identifies the resource as contracts/frameworks approaching renewal. The purpose is clear and distinct, though it does not explicitly contrast it with sibling tools.

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 gives clear usage context: use this when you need renewal/forecast signals for contracts or frameworks approaching renewal. It lists filters and defaults, but does not mention when to prefer an alternative tool such as get_company_opportunities or research.

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