pubchem-mcp-server

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

Annotations cover read-only/idempotent traits, but the description adds valuable behavioral context: it specifies the exact data fields returned (signal word, pictograms, H-codes, P-codes) and discloses data provenance ('sourced from PubChem depositors') and attribution practices.

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?

Two efficiently structured sentences with zero waste. The first sentence defines the operation, the second details return values and data source—every word earns its place.

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 has a single parameter, good annotations, and an output schema, the description is complete. It covers functionality, return content structure, and data sourcing without needing to replicate detailed return value specifications.

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?

With 100% schema description coverage, the schema already fully documents the 'cid' parameter. The description adds no specific parameter guidance, meeting the baseline expectation for high-coverage schemas.

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 uses a specific verb ('Get') and clearly identifies the resource (GHS hazard classification and safety data). It distinguishes itself from siblings like pubchem_get_bioactivity and pubchem_get_compound_image by specifying the exact domain (safety/GHS 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?

While it doesn't explicitly name alternatives, the description provides clear context for when to use this tool (when seeking GHS classifications, signal words, pictograms, H-codes, and P-codes) which distinctly separates it from bioactivity or general compound detail tools.

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