compras_obter_resource

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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds value by stating the exact return structure, the mime-type-dependent raw content format, and the `_erro` fallback instead of propagating exceptions.

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 compact and well organized: a one-sentence purpose, concise return behavior, a clear output block, and an error condition. Every sentence contributes useful information, and the key behavior is front-loaded.

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?

This is a simple one-parameter, read-only tool with rich annotations and full schema coverage. The description covers purpose, return fields, content format, and error behavior, so an agent has everything needed to invoke and interpret the result 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 100%, and the schema itself explains URI semantics, gives discovery guidance, and provides examples. The tool description adds only the brief reference to 'pela URI', so it does not meaningfully improve on the schema.

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 opens with 'Lê o conteúdo de um MCP Resource pela URI', naming a specific verb, resource type, and key selector. It clearly separates reading a resource from listing resources, though it does not explicitly name a sibling alternative in the main description.

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?

Usage is implied: call this when you have a resource URI and need its content or metadata. The parameter schema adds the useful prerequisite 'Use `compras_listar_resources` para descobrir URIs disponíveis', but the description itself does not discuss when not to use it or contrast it with sibling tools like `compras_obter_prompt`.

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