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

Annotations already declare non-read-only, idempotent, non-destructive behavior; the description usefully adds that the 'account' scope is required and that the call is free of credit cost. However, for a settings tool where every parameter is optional, it never states whether omitted fields are preserved or reset — the single most important behavioral question here.

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?

One dense sentence that front-loads the main action and appends the constraints. Little waste, though the parenthetical '(podcast + enabled)' and the phantom 'weekly day' clause slightly muddy the parse.

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?

Five all-optional parameters, no output schema, and low schema coverage demand more from the description. Two parameters are undocumented, one documented concept is missing from the schema, and merge-vs-replace semantics are absent, leaving an agent unable to call this safely for partial updates.

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 only 20%, so the description must carry the load. It explains enabled, frequency (daily/weekly), and podcast (constrained to a followed podcast), but 'start' and 'points' are left completely unexplained, and 'weekly day' is described with no matching schema property — a genuine source of confusion.

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?

Specific verb and resource: turning the summary email on/off, setting frequency, and adding a followed podcast. It is clearly distinguishable from siblings like follow_podcast or get_account. Minor deduction because it references a 'weekly day' setting that has no corresponding schema property, while two real properties (start, points) go unmentioned.

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 implies when the tool applies (configuring the summary email) and gives one combination rule — 'podcast + enabled' must be supplied together to include a podcast. There is no explicit when-not guidance and no pointer to a sibling for reading current settings, so usage is inferred rather than stated.

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