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

Beyond the annotations (readOnly/openWorld/idempotent), the description discloses the pricing model ('1 credit + 2 credits per space returned'), the 404 failure mode, and the default omission of listeners with the reason (list length and privacy of individuals). These are exactly the non-obvious traits annotations cannot express.

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?

Four compact sentences: identity/return shape first, then the opt-in flag, then the error case, then cost. Nothing is repeated and each sentence adds a distinct fact.

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?

There is no output schema, so the description carries the return-shape burden itself and does so by enumerating the Space's fields and states. With only two parameters and read-only annotations already covering safety, an agent has everything needed to call it correctly and anticipate cost and 404s.

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 both parameters — the URL-derived id and the listeners enum with its privacy rationale — are already fully documented in the schema, so the description's 'Listeners are included only with listeners=true' largely restates it. Baseline 3 applies since the schema does the heavy lifting.

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?

The description opens with a specific verb+resource ('Get an X Space') and immediately defines it as 'a live audio room', then enumerates the fields returned (title, state, schedule, host, speakers, audience counts, replay availability). No sibling tool retrieves Spaces, so there is no ambiguity against the get_x_post/get_x_user/get_x_list family.

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?

It gives clear operational context: listeners are opt-in via `listeners=true`, a missing Space yields 404, and cost scales per Space returned. There is no sibling alternative to steer away from, so no explicit exclusion is needed; the only modest gap is the absence of a stated 'use when you have a Space id or URL' framing, which the schema's id description partly covers.

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