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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuine value by defining what each kind contains and flagging that unsubscriber/complaint entries carry personal data (email, phone), but says nothing about pagination behavior or result shape.

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, front-loaded sentences with no filler; the kind enumeration comes first and the raw endpoint path is appended for API traceability. Slight duplication between 'by kind' and the endpoint template, but nothing wasteful.

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?

There is no output schema, and the description never says what a result looks like or that the response is paginated (offset/next_offset, limit default 50). For an 8-parameter paginated list tool, that leaves an agent to infer return shape from the schema alone.

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 every parameter including limit, offset and the modified_after/before bounds is already documented in the schema. The description only echoes the filterable fields (email, phone, modification date) and omits limit/offset entirely, adding little beyond the structured data.

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 ('Entries of a blacklist') and enumerates the three kinds with short glosses, which distinguishes it from sarbacane_list_blacklists (which lists the blacklists themselves). It never names that sibling explicitly, so the differentiation is inferential rather than stated.

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?

The description implies retrieval and filtering ('Filter by email, phone or modification date') but gives no explicit when-to-use guidance or exclusions. The prerequisite that a blacklist_id must come from sarbacane_list_blacklists appears only in the schema parameter description, not here.

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