list_ticket_labels

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds real context beyond that: the list ordering, the empty-until-defined state, the fact that labels are referenced by ID in labelIds, and that label membership decides nothing about a ticket. That is meaningful read-semantics an agent cannot get from structured fields.

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?

Front-loaded with the core purpose, then layers prerequisites and empty-state. Mostly earning its place, though the sentence about labels being 'the team's own vocabulary' is slightly philosophical and could be tightened.

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?

With no output schema, the description compensates by describing the return shape (name, colour, project-defined order) and the empty-list case. Combined with complete parameter documentation and a clean read-only annotation profile, an agent has everything needed to call and interpret this tool.

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% and there is a single required projectId documented as coming from list_projects, so the schema carries the burden. The description adds no syntax or format detail about the parameter beyond that. 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?

States a specific verb and resource — listing a project's ticket labels — and immediately characterizes the returned items as 'a name and a colour, in the order the project picks them'. An agent can distinguish this from siblings like list_tickets or create_ticket without opening any schema.

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 routes usage: 'read this before creating or updating one', tying the tool to the labelIds a ticket carries. It also sets a clear negative expectation — 'no tool here creates one' — so the agent won't hunt for a label-creation sibling.

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