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

Annotations already establish readOnlyHint=false and destructiveHint=false, so the agent knows this mutates state additively. The description's 'add a message' is consistent with that, but adds no extra behavioral detail such as whether replies notify staff, whether a closed ticket can be replied to, or permission requirements.

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?

One front-loaded sentence states the action and scope, followed by a compact API reference link. No filler or redundancy.

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 mutation with no output schema, the description covers purpose and typical use, but omits failure behavior (unknown/closed ticket), permission needs, and any return indication, leaving meaningful gaps.

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 0%, so the description must carry the burden. It implies body is the message text and ticket_id must reference an existing ticket, but provides no format, length, or constraint guidance for either parameter.

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?

Specific verb (add a message) plus resource (existing Tango support ticket), which clearly separates it from submit_support_request (creating a ticket) and list_support_requests. It stops short of explicitly naming those siblings, so an agent must infer the boundary from 'existing'.

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?

Gives three concrete situations for use (answer a staff question, supply requested error output, confirm a fix), which is solid context. It does not state when not to use it or name submit_support_request as the alternative for new tickets.

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