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

Annotations already declare this is a non-read-only, non-destructive, non-open-world mutation, so the safety profile is covered. The description adds real value by disclosing patch semantics ("without changing omitted preferences") and the authorization prerequisites. However, it does not say what happens when a field is set to null or an empty array, and the merge-style partial update sits slightly awkwardly against idempotentHint=false.

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?

Three tight sentences with no filler: the mutation scope and partial-update contract come first, followed by ownership and permission constraints. Every clause conveys a distinct constraint an agent needs.

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?

An output schema exists, so return values need not be described, and the auth/ownership requirements are well covered for a mutation. The gap is the nine-parameter payload with zero schema descriptions, five of which are unexplained and include consent-related fields (email, emailConsent, browser) where mis-setting could have side effects.

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 carry the load, and it names only four of nine parameters (theatres, formats, triggers, cadence). The meanings of id, email, browser, timezone, and emailConsent are not explained anywhere, and no guidance is given on enum values or the maxItems limits beyond the schema itself. Partial credit is earned for signaling that unspecified fields are left untouched.

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 ("Update a saved follow") and enumerates the mutable facets: theatres, formats, triggers, cadence. An agent can distinguish it from create_alert/delete_alert, though the naming drift between "alert" (tool) and "follow" (description) and the absence of any mention of pause_alert/resume_alert leaves some ambiguity about the full alert lifecycle.

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 clear when-to-use conditions: only for the connected owner's own alert, only for an entitled owner with alerts:write. It also implies when-not-to-use via the ownership restriction. It stops short of explicitly routing the agent to siblings such as pause_alert, resume_alert, or delete_alert for lifecycle changes.

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