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

Discloses the non-obvious side effect that a "Your First Live Project" is created when none exists, which explains and justifies the readOnlyHint=false annotation on a get-style tool. It also names the exact error code and accompanying field for the ambiguous case, letting the agent recover without guessing.

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 short paragraphs, each doing one job: what is returned, how to disambiguate, what happens on the empty case. Slightly more prose than strictly needed, but no filler and the purpose statement leads.

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 single-parameter tool with an output schema and full annotation coverage, this covers everything an agent needs: return shape hint, disambiguation path, error code, and the auto-creation edge case that would otherwise surprise it.

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% and the single parameter is already documented, so the baseline was met by the schema. The description still adds decision logic the schema cannot express: default to omitting the id, and what to do with the returned id list when ambiguity occurs.

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 live project") plus the key payload field (stream_count). This cleanly separates it from the sibling list_live_projects and from get_live_stream, which all deal with adjacent but different resources.

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 explicit conditional guidance: omit ls_project_id when the owner has a single project, retry with an id from live_projects when the call returns live_project_ambiguous, and inform the user when a default project is auto-created. Each branch of use is spelled out rather than implied.

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