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

Annotations already cover read-only, idempotent and non-destructive behavior, but the description adds genuinely non-obvious context: unsubscribed/bounced/complained contacts are hidden unless include_suppressed is true or a status is given, and results are summaries only (no email body). No auth or rate-limit notes, but the suppression rule is exactly the kind of behavior an agent would otherwise guess wrong.

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?

Front-loads the core action and scope, then layers filtering, suppression behavior, return format, and sibling routing. Every sentence carries distinct information and none is redundant with the schema or annotations.

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 steps in to explain the return shape ('summary for each contact, no email body content'), and all six parameters are covered. An agent has enough to call this correctly without further inference.

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%, so all six parameters (tag, limit, offset, search, status, include_suppressed) are already documented in the schema. The description references filtering by status/tag and pagination but adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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 (list) and resource (contacts) with scope (connected Meisa product, reverse-chronological order). Explicitly distinguishes itself from the sibling meisa_get_contact by routing single-contact lookups elsewhere, so an agent can tell the two apart 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?

Gives concrete trigger phrases ('see their subscriber list, browse contacts, or check how many contacts they have') and names one alternative (meisa_get_contact). However, it omits meisa_search_contacts, which is a very close sibling, leaving that routing decision to inference.

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