Get a service URL

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

Adds behavior the annotations cannot express: it reads local runtime evidence only, never guesses a hostname, and can fail with a specific url_not_ready error until the daemon publishes a URL. It also explains the polling remedy via wait, which is exactly the operational detail an agent needs to handle the failure path.

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?

Three sentences, front-loaded with the core action, then usage context, then failure/polling behavior. No filler and nothing redundant with the schema.

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?

An output schema exists, so return values need not be described; the description instead covers the two things an agent must know beyond schema: the trigger condition and the failure/polling behavior. Nothing essential is missing for a two-parameter read 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 coverage is 100%, so the baseline is 3, but the description goes slightly beyond by tying the wait parameter to the url_not_ready failure mode (pass wait to poll), explaining why the parameter exists rather than just its format.

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 ('Return one registered service's exact runtime URL') and narrows the scope to a single service, which distinguishes it from collection-oriented siblings like list or status. The word 'exact' and 'runtime' frame what makes this lookup non-trivial.

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 concrete trigger conditions: use it after add, or after a needs_login share has been authorized. That is clear usage context, though it never names an alternative tool (e.g., how it differs from status or list) nor states when this tool should be skipped.

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