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

Annotations declare a mutating, non-idempotent, non-destructive write with openWorldHint=false, and the description adds real context beyond that: the 'confirm=false previews' dry-run behavior and the no-pixel prerequisite. It omits permissions/auth needs and what happens on repeated calls, so it is strong but not exhaustive.

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 leading paragraph is front-loaded with the differentiator, and the per-source bullet list is easy to scan. Minor deductions for the stray mixed-language aside ('Meta'da %95 eşiği YOKTUR') and some redundancy between the prose and the bullets.

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 7-parameter mutation with an output schema present, the description covers the tricky parts: source/event vocabulary, retention bounds, and the preview flag. It lacks account_id/name guidance and any note on where the audience ID is returned, but nothing critical to correct invocation is missing.

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 0%, so the description must compensate, and it largely does: it maps source→source_id provenance (list_meta_page_posts, list_meta_pages), enumerates valid event values per source, and gives retention_days bounds (1-365) and confirm semantics. It leaves name and account_id undocumented, so it is not fully compensating.

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 ('builds a Meta retargeting audience from ENGAGEMENT') and immediately scopes it against the website-traffic audience siblings ('instead of website traffic', 'NO PIXEL AND NO WEBSITE TRAFFIC NEEDED'). An agent can distinguish this from create_meta_website_audience, create_website_audience, or create_meta_lookalike_audience without opening a 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 a clear when-to-use context ('the only realistic retargeting option for accounts with a small or brand-new site' and 'best lookalike seed you can get early on'). It strongly implies the alternative (website-traffic audiences) but never names it or states the explicit selection condition, so it stops short of a full routing rule.

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