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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered without description help. The description adds the definition of a destination and the REST endpoint it mirrors, but says nothing about pagination, ordering, or an empty-destination result.

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?

Two short, front-loaded sentences with no padding; the resource and its scope come first. The trailing endpoint reference is mildly redundant but cheap and occasionally useful for API-familiar agents.

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 single-parameter read tool with full annotation coverage and no output schema, the description supplies enough to call it correctly. Missing only return-shape and pagination notes, which are minor here given the annotations.

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% and the single 'stream' parameter is already documented as a Stream UUID, so the schema carries the load. The description only implicitly ties the parameter to a stream, adding no syntax or format detail beyond the schema baseline.

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?

The description gives a specific verb+resource (list a stream's multistream destinations) and even parenthesizes what a destination is, which helps an agent distinguish it from list_streams, list_tags, and list_media. It does not explicitly name the create/update/delete destination siblings, but the read-vs-write split is obvious from the 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?

There is no statement of when to use this tool versus alternatives, and no prerequisites (e.g., that a stream must exist or that destinations are only meaningful for restreaming setups). Usage is only weakly implied by the phrase 'a stream's destinations'.

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