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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so the safety profile is covered by structured data. The description adds genuinely useful behavior the annotations don't: the 200,000-character truncation with a note when longer, and the inclusion-by-default filtering semantics. That is real added context, though it says nothing about auth needs or error behavior.

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?

The most important fact – the truncation limit and where to go instead – is front-loaded in the first sentence, and the trailing 'POST /jobs/download' is a compact endpoint marker. No sentence is redundant.

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?

With no output schema, the description still explains the return value (CSV text of submitted columns plus email_status) and its truncation caveat. Combined with the annotations covering side effects, an agent has everything needed to call this correctly.

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 every parameter carries its own default note, so the schema does the heavy lifting. The description still adds the framing that the booleans are result-type toggles that default to inclusive, which helps an agent understand the filtering model as a whole rather than parameter-by-parameter.

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 states exactly what the tool returns – job results as CSV text containing the submitted columns plus email_status – and names the sibling tool (neverbounce_get_job_results) it differs from. An agent can distinguish it from neverbounce_get_job 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?

It gives the explicit escape hatch: 'use neverbounce_get_job_results to page through large jobs', and explains the filtering behavior ('set a type to false to leave it out'). The when-to-use-this vs. when-to-use-the-alternative decision is fully spelled out.

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