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

Beyond the annotations (readOnly=false, destructive=false), the description discloses that the spot is pending until the human completes payment, that Stripe is in test mode, and that no real money moves. This is useful behavioral context and does not contradict the annotations.

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?

Roughly six short sentences, front-loaded with the action and required inputs. It is slightly redundant ('Stripe test mode' and 'Test cards only, no real money moves' say similar things), but overall tight and readable.

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 tool with no output schema, it names the return value (commit link), states the pending state before card payment, and identifies test mode. It doesn't cover optional 'name' or error cases, but the essential behavior is sufficiently complete for this complexity level.

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?

The schema already describes all five parameters at 100% coverage, so the baseline is 3. The description restates the core required params (chain slug, max price, email, invite code) but adds no new parameter-level detail beyond the schema.

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 uses a specific verb and resource ('Take a spot on a chain') and defines the output (commit link). It is clear what the tool does, but it never distinguishes itself from the sibling 'join_chain', so it isn't fully differentiated.

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 clearly states the required inputs and the flow: get a commit link, send it to the human, and have them put a card down to make the spot real. This gives clear context for when to call it, though it doesn't explicitly say when not to use it or name an alternative like 'join_chain'.

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