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

Goes well beyond annotations: discloses that the guest is not notified, that guests can still change their own answer later, that the change is reversible with one call, that it needs no confirmation, and the required Cotlet API key scope. This is exactly the behavioral context annotations can't convey.

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?

Front-loaded with the core action, but it repeats the same point three times ('The guest is not notified', 'Evite does not tell the guest', 'It reaches no one'), which is redundant padding rather than earning sentences.

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 4-param mutation with no output schema, it covers the action, side effects, reversibility, and auth requirement. Only minor gaps remain: it doesn't clarify what happens if party_size is omitted or the return behavior.

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 both the enum (yes/no/maybe) and party size are already documented in the schema. The description's mention of 'yes, no or maybe, with a guest count' merely restates schema content, adding no new syntax or format detail.

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 ('Set a guest's response and party size as host') plus the UI equivalent ('Edit under View Guest List'). It clearly distinguishes itself from siblings like evite_list_guests, evite_add_guests, and evite_message_guests without opening a schema.

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?

Strong context on when this applies: as host, without notifying the guest, and reversible ('one more call undoes it, so it runs without asking'). It does not explicitly name alternative siblings (e.g. message_guests) or give exclusion conditions, so it stops short of a 5.

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