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

Annotations already indicate readOnlyHint=true, and the description adds concrete behavioral details: it is best-effort and may return a clear error on deployments with introspection disabled. This goes beyond the annotation by setting expectations for failure modes.

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 sentences, with the primary purpose front-loaded and the fallback condition stated in the second. Every clause earns its place; no redundant restatement of the title or annotations.

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?

For a parameterless, read-only introspection tool, the description covers what the query returns (schema types, fields, flags, evaluation context) and the one notable failure mode. A standard GraphQL introspection response format is widely known, so omitting a detailed return schema is acceptable.

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?

The tool has zero parameters and the schema coverage is effectively 100%, so there is no parameter meaning for the description to add. The 0-param baseline of 4 applies, and the description's focus on output scope 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?

States a specific verb ('introspect'), resource ('GraphQL schema'), and scope ('all types and fields, including the available flags and the shape of the evaluation context'). This clearly differentiates it from sibling tools like hypertune_query or hypertune_list_flags.

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?

Explicitly notes when the tool may fail (disabled introspection) and directs the agent to hypertune_query with a known flag name as the alternative. This gives a when-not and a named sibling, satisfying the highest bar for usage guidance.

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