segment_list_destinations

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld behavior, so the safety profile is covered. The word 'all' hints there is no filtering, but pagination behavior, rate limits, and error/auth conditions are unstated — with annotations present, this is an acceptable but thin addition.

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?

A single front-loaded sentence with zero filler. It is efficient; the only reservation is that it is so short it leaves necessary context unaddressed, though that is a completeness issue rather than verbosity.

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 simple two-parameter read tool with full schema coverage and annotations, the description is minimally sufficient. However, there is no output schema, so nothing tells the agent whether results are paginated, what a destination record contains, or what an empty result implies.

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 api_key and source_id are already fully documented. The phrase 'connected to a Segment source' reinforces that source_id scopes the results, but adds no format, validity, or retrieval guidance beyond the schema.

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 ('List all destinations') and scopes it to a Segment source, which distinguishes it from the sibling segment_list_sources and segment_get_source. It is clear but terse, offering no detail beyond the operation name.

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?

No guidance on when to use this versus segment_list_sources/segment_get_source, and no hint that a source_id must first be obtained (presumably from segment_list_sources). The agent is left to infer the workflow entirely.

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