MCP Weather Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the tool returns a city ID, which is useful, but doesn't cover other behavioral traits such as error handling, rate limits, authentication needs, or what happens with ambiguous inputs. For a lookup tool with zero annotation coverage, this leaves significant gaps in understanding its operation.

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 two sentences, front-loaded with the core purpose and followed by a practical note about the return value's use. Every sentence earns its place by adding clarity and utility without any waste or redundancy, making it highly efficient.

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?

Given the tool's low complexity (a simple lookup), no annotations, no output schema, and high schema coverage, the description is adequate but incomplete. It covers the basic purpose and return usage but lacks details on behavioral aspects like errors or performance, which are important for a tool with no structured safety or output information.

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%, so the schema already documents both parameters thoroughly. The description adds minimal value beyond the schema by mentioning lookup methods (name, ID, coordinates) and the purpose of the returned ID. It doesn't provide additional syntax, format details, or examples beyond what's in the schema, meeting the baseline for high coverage.

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 tool's purpose: 'Look up city information by name, ID, or coordinates.' It specifies the verb ('look up') and resource ('city information'), and mentions multiple lookup methods. However, it doesn't explicitly differentiate from sibling weather tools beyond noting the returned city ID can be used with them, which is helpful but not a full distinction.

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 implies usage by stating the tool returns a city ID for use with other weather tools, suggesting it's a prerequisite for those siblings. However, it doesn't provide explicit guidance on when to use this tool versus alternatives (e.g., direct weather queries) or any exclusions. The context is clear but lacks detailed alternatives or when-not scenarios.

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