Pythia MCP

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

With no annotations provided, the description carries full burden but discloses minimal behavioral traits. It mentions 'search' and 'new Higgs measurement data', implying read-only retrieval, but doesn't cover aspects like rate limits, authentication needs, pagination, result format, or error handling. This is inadequate for a search tool with 5 parameters.

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, efficient sentence with zero waste—it directly states the tool's purpose without redundancy. It's appropriately sized and front-loaded, making it easy to parse.

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 complexity (5 parameters, no annotations, no output schema), the description is incomplete. It lacks behavioral context (e.g., how results are returned, error cases), doesn't explain the relationship between parameters (e.g., if 'query' overrides others), and provides no output details, leaving significant gaps for agent usage.

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 all 5 parameters thoroughly. The description adds no additional parameter semantics beyond implying Higgs-specific filtering, which is partially covered by the schema's enum/descriptions. Baseline 3 is appropriate as the schema does the heavy lifting.

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 verb ('search') and resource ('HEPData repository'), specifying the target data ('new Higgs measurement data from ATLAS and CMS'). It distinguishes from some siblings like 'fetch_hepdata_record' (retrieves specific records) or 'list_experimental_data' (lists without filtering), but doesn't explicitly differentiate from 'search_cern_opendata' (which searches different data).

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?

No explicit guidance on when to use this tool versus alternatives like 'search_cern_opendata' (for CERN Open Data) or 'get_latest_higgs_data' (which might retrieve pre-curated data). The description implies usage for Higgs data searches, but lacks context on prerequisites, exclusions, or comparative scenarios.

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