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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds genuinely non-obvious behavior: the call is free, only the current version of each plan is returned, and omitting `ano` defaults to the current year onward. It does not describe pagination limits or result caps, so 4 rather than 5.

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 purpose and returned fields are front-loaded, and each subsequent clause (free, current-version-only, default year, alert alternative, HTML accept) carries distinct information. It is dense but not padded; a slight cost is that several distinct ideas are packed into a single run-on sentence.

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 listing the returned fields, and it covers scope (pre-tender phase), freshness limits, default filtering, cost, and the sibling route for alerts. An agent has everything needed to select and invoke it 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 coverage is 100%, so all three parameters (q, ano, pagina) are already documented in the schema. The description's note about the `ano` default largely restates the schema text, adding little new meaning, so the baseline 3 applies.

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 states a specific resource (annual procurement plans / PCA published on PNCP) and pins the exact lifecycle phase — 'before the tender opens' — which separates it from search_tenders and get_procurement. It even enumerates the returned fields (item, agency, quantity, estimated value, desired date), so an agent knows precisely what this tool yields.

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 context (use for planning data before a tender exists) and routes the agent to create_alert when the goal is knowing when the tender opens, plus an Accept: text/html tip for the UI tab. What's missing is an explicit when-not / direct contrast against the tender-search siblings, so it falls short of a 5.

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