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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description reinforces 'Read-only' without contradicting. It then goes well beyond annotations: delivery counts are attempts not confirmed deliveries, recipientCount is delivery rows once sending starts, and null means NOT COMPUTED never zero, explaining exactly why filtered audiences and get_broadcast_details yield null. This is precisely the semantic context an agent needs to avoid misreading results.

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 purpose and the read-only note, then layers semantics and alternatives. It is dense and long, but nearly every sentence carries distinct information (null semantics, AND combination, action routing). The recipientCount/null passage is slightly dense and could be tightened, keeping it from a 5.

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 6-parameter list tool with no output schema, the description covers purpose, filtering semantics, return-value pitfalls (null vs zero), and sibling alternatives. An agent has everything needed to call it correctly and interpret the counts.

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% and each parameter is documented in the schema, so the baseline is 3. The description adds genuine cross-parameter meaning the schema lacks — 'Filters combine as AND' — which materially affects how an agent composes botId, status, and isRecurring, though it doesn't comment on paging or the applicationId failure mode beyond what the schema already states.

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?

Opens with a specific verb (List) and resource (broadcasts) plus the fields returned (status, schedule, delivery counts). It also explicitly names the siblings it is not — get_broadcast_details for one broadcast, apply_actions/create_broadcast for creation — so an agent can route without opening any 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 use/use-not routing: 'Use get_broadcast_details for one broadcast's full breakdown' and 'To CREATE or SEND a broadcast use apply_actions', down to the specific actions and status. It covers both the read-side alternative and the write-side path the agent would otherwise guess at.

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