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

Annotations already declare the tool as read-only, idempotent, and non-destructive, so the description does not need to cover safety. It adds a useful explanatory detail about MeSH tree numbers showing hierarchical paths with an example, but it does not disclose much additional behavioral context beyond what the title and annotations imply.

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 front-loaded with a clear purpose statement and uses compact bullet points. Some redundancy exists between the opening sentence and the first bullet, but overall it is appropriately sized and easy to scan.

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, with one required parameter, a fully documented schema, annotations covering side effects, and an output schema available. The description provides enough information for correct invocation, including a concrete tree-number example. It lacks explicit sibling differentiation, but that is not critical for this tool's completeness.

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%, with mesh_id fully documented by its pattern and examples. The description mentions MeSH descriptors and tree numbers, but it does not add new parameter-level semantics beyond what the schema already provides, so the baseline of 3 applies.

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 opens with a specific verb and resource: 'Get the tree hierarchy location(s) for a MeSH descriptor.' This clearly identifies the tool's function and differentiates it from related MeSH tools like mesh_descriptor or mesh_search, though it does not explicitly name sibling alternatives.

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 provides explicit use cases via bullet points: seeing where a term fits in the MeSH hierarchy, understanding broader/narrower relationships, and finding related terms in the same branch. It gives clear context for when to use the tool, though it does not state when not to use it or directly point to an alternative.

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