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

Annotations already mark this read-only, idempotent and non-destructive, and the description still adds real context: it returns the request page URL plus a text-message alternative, and passing event_date additionally reveals whether the DJ is already blocked. The explicit 'does not place a booking' constraint is exactly the kind of behavioral disclosure an agent needs to avoid over-promising.

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-loads the purpose, then trigger phrases, then return content, then the sibling routing — a sensible order with no filler sentences. Slightly long because the trigger-phrase list and the request_booking explanation both run a couple of clauses, but each carries routing value.

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 two-parameter, read-only lookup with no output schema, the description covers what it returns, what changes when event_date is supplied, and how it relates to request_booking. Only gap is that the exact shape of the returned 'next steps' is described loosely rather than concretely.

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 the baseline is 3, but the description goes beyond the schema by explaining the consequence of supplying event_date (an availability/blocked check) rather than just its format. id_or_slug provenance (search_djs or get_dj) is already in the schema, so no extra credit there.

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 ('How to book or request one specific DJ') and immediately clarifies the actual behavior — it returns next steps rather than placing a booking. It explicitly distinguishes itself from request_booking, so an agent can route correctly without opening either 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?

Gives explicit trigger vocabulary ('book', 'request', 'hire', 'get a quote', 'how do I book') and names the alternative (request_booking) with the condition that selects it (the person must sign in with DJfindr). It also states an exclusion: 'This tool does not place a booking.'

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