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

With no annotations, the description carries the full disclosure burden but does add genuinely useful economics: 'Free — costs 0 credits' and the fact that map_constellation runs per account afterwards. It omits duplicate handling, what happens to accounts that fail to resolve, and whether the call is idempotent — meaningful gaps for a write operation.

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?

Three short sentences, front-loaded with the core action, then sequencing, then cost. No sentence is filler and nothing important is buried.

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 2-parameter tool with fully documented schema, no annotations and no output schema, the description covers purpose, downstream effect and cost. The main missing piece is return behavior (count added, per-account failures), which the absence of an output schema leaves unexplained.

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%, including a description on the accounts array (1-500 per call), so the schema already documents both parameters. The description only clarifies that an account is 'a company you want to reach' and adds nothing about tier, employee_count, or linkedin_company_id — baseline 3 is appropriate.

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 (add) and specific resource (target companies into a Constellation campaign), which separates it from generic collection/segment tools in the sibling list. It stops short of explicitly contrasting with add_to_collection or add_to_segment, but the noun 'Constellation campaign' is distinctive enough for an agent to route correctly.

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?

'Each account is a company you want to reach; map_constellation is then run per-account' supplies the downstream workflow, letting an agent place this tool in a sequence. There are no explicit exclusions or prerequisites (e.g., when not to add an already-present account), so it falls shy of a 5.

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