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

Annotations already mark this as a non-read-only, non-destructive, non-idempotent, closed-world write. The description adds a real behavioral fact beyond them: duplicate names in any casing cause an error, which tells the agent the call can fail on a semantic constraint. It omits permissions/auth requirements and the success response shape.

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 tight sentences with the primary action front-loaded and the failure condition immediately after; no filler and nothing to trim.

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 simple two-parameter create tool whose annotations carry the safety profile and whose schema fully documents inputs, the description covers purpose and the key failure mode. With no output schema it could say what a successful call returns, which is the only notable gap.

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 types and the 64-character limit. The description restates the case-insensitive uniqueness rule that the schema's name description already states, adding no syntax or format detail beyond the schema.

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+resource+scope ('Create a new segment for a project'), which cleanly separates it from update-segment-tool, delete-segment-tool, and the other create-*-tool siblings by resource. It does not name any alternative, but the intent is unambiguous.

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 the create verb and the uniqueness rule, but there is no explicit when-to-use/when-not guidance and no mention of prerequisites (e.g., that project_id must reference an existing project) or of update-segment-tool as the alternative for modifying an existing segment.

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