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

Annotations already cover the safe-read profile (readOnlyHint, idempotentHint, destructiveHint=false), so the description is free to add genuinely new behavior: `email` is null for hand-added or pitch-form deals, `body` is null for emails with no text (e.g., a bare deck), and the email persists with the company after promotion into the portfolio. These edge cases and the data-lifetime rule are not derivable from any structured field.

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 payload of the tool (who sent/forwarded, subject, body) is front-loaded in the first clause, followed by the differentiator and then the null/lifetime caveats. Every sentence carries a distinct fact — no filler or restatement of the tool name.

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 carries the full burden of describing return values and does so field by field (sender, forwarder, subject, stripped body). It also covers the two null cases and the post-promotion persistence, leaving nothing an agent needs to call and interpret this tool.

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?

There is a single `slug` parameter at 100% schema description coverage, so the schema fully documents its meaning ('the pitch (or company) to read, by slug'). The description adds no additional format or resolution detail about the slug beyond what the schema already states, which is the baseline-3 case.

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 names a specific verb+resource (read the pitch email) and enumerates exactly what is returned: sender, forwarder into Signed, subject, and plain-text body with forwarding headers stripped. It explicitly differentiates itself from the sibling get_pitch_analysis, so an agent can choose between them without opening either 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 states the condition that selects this tool ('read this for the founder's own words — the ask, the traction, who made the intro') and names the alternative that should be used otherwise ('which get_pitch_analysis only summarizes'). Explicit when-to-use plus a named alternative is the top of the scale.

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