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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety burden is lifted. The description adds domain behavior beyond that: the default result set is the house cast plus open characters, the meaning of the can_ask_out flag, and the default scoping. It omits return ordering/pagination behavior.

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 action and scope, and no sentence is pure filler. It is dense and slightly run-on in places ('can_ask_out says who you can book straight away'), which keeps it out of the top tier.

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 search tool with no output schema and full schema coverage, the description supplies the scope model, default filtering, and alternative routing an agent needs. It does not describe result shape beyond the can_ask_out flag, but nothing essential is missing for correct invocation.

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% with per-parameter descriptions for all seven params, so the baseline is 3. The description only restates the free-text/traits filters and the open_only override, which the schema already documents, adding little 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+resource ('Search characters') and defines the searchable pool (house cast plus characters whose creator opened them to dates), which is more than a restatement of the name. It does not explicitly contrast itself with close siblings like list_cast or find_matches, so it falls short of a 5.

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 real routing guidance: it names swipe_deck/swipe as the path for a first date with anyone not flagged can_ask_out, and tells the agent to set open_only: false to browse everyone. It stops short of stating when not to use this tool versus list_cast/my_characters, so no explicit exclusion set.

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