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

Annotations already declare readOnlyHint=true and destructiveHint=false, providing the safety profile. The description adds the notion of 'full details' but does not disclose behavior like error handling, return format, or not-found behavior. It offers some context beyond annotations but not much.

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 sentence, front-loaded with the verb and object, and contains zero filler words. It is appropriately compact for a simple get-by-ID tool, though it lacks elaboration that could be useful. It is concise without being under-specified.

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?

The tool is simple (one parameter, read-only) and the description states the action and identifier. However, there is no output schema and the description does not explain what 'full details' includes or the behavior for invalid IDs. This is a clear gap, though not severe for such a straightforward 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 100%: the only parameter, service_id, is described as 'The unique service ID.' The description's phrase 'by its ID' reinforces this. No additional semantic detail is added beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 'Get full details of a single marketplace service by its ID' uses a specific verb (Get), identifies the resource (marketplace service), and clarifies scope (single, by ID). This clearly distinguishes it from sibling tools like get_agent and get_reputation, leaving no ambiguity about what this tool does.

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: if you have a service_id and need full details, use this tool. However, the description does not explicitly state when to use this over alternatives (e.g., marketplace_search) or mention any prerequisites or non-conditions. No exclusions or alternative tool references are provided.

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