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

Annotations already mark the operation as read-only and idempotent. The description adds useful behavioral context beyond the annotations: the tool returns a URL to a PDF, not the PDF itself, and the input hash comes from the search response. No contradiction with 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?

A single, well-structured sentence that is front-loaded with the main purpose and includes the necessary parameter relationship. No filler or redundant content.

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 simple one-parameter lookup tool with strong annotations, the description is complete enough: it states what is returned, the required input, and where the input comes from. No output schema is needed to understand the basic behavior.

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%, but the description compensates by explaining that 'hash' is the field 'retornado na busca'. This gives the parameter practical meaning and provenance, even though it does not describe the hash format or length.

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 the action: 'Retorna a URL da certidão (PDF) de uma comunicação do DJEN' and specifies the input dimension ('pelo seu hash'). It also distinguishes itself from the sibling search tool by retrieving a certificate URL for an already-known hash.

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?

The description explains the intended workflow: use the hash returned in the search results from the DJEN search tool. It gives clear context for when to call this tool, though it does not explicitly mention when not to use it or name alternatives.

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