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

Beyond the readOnlyHint and openWorldHint annotations, the description discloses the data source and license, result cap (up to 20 per call), pricing model ($0.002 USDC per successful call via x402 on Base, Solana, or Arc), and that failed calls are not charged. This is rich, actionable behavioral context for an agent managing cost and expectations.

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 front-loads the core purpose, followed by scope, result limit, and pricing. Every sentence carries useful information, though the pricing sentence is slightly dense and could be split for readability.

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 an output schema exists, the description need not explain return values, yet it helpfully lists them. It covers source, scope, result limits, and cost. Minor gaps include no explicit pagination or rate-limit behavior beyond the per-call cap, but overall it is complete enough for correct invocation.

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 both parameters are already documented with constraints and defaults. The description adds only a general reference to 'matching a term' and 'up to 20 per call,' which aligns with the schema without adding format or syntax details beyond it. Baseline 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 states a specific resource (Reactome curated human biological pathways), the matching behavior, and the exact fields returned: stable ID, pathway name, disease status, and summary. It distinguishes itself from sibling pathway tools implicitly through the Reactome source and human-only scope, but does not explicitly contrast with alternatives like KEGG.

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 by 'matching a term' and the human-only constraint, but there is no explicit guidance on when to choose this tool over siblings such as health_kegg_pathway_genes or health_string_protein_networks. No when-not conditions or alternatives are named.

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