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

Annotations already carry destructiveHint=true, idempotentHint=true and readOnlyHint=false, but the description adds real behavioral context beyond them: the REPLACE semantics for competitors/audiences (what actually gets overwritten), size caps (20 items / 120 chars), the temporal scope ('Applies to drafts written from now on'), and 'Sends nothing' (consistent with openWorldHint=false). Nothing here contradicts the annotations.

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-loaded with the core effect and zero filler; the destructive REPLACE warning is placed prominently. The opening sentence is dense with a mid-sentence parenthetical that makes it slightly harder to parse than the ideal, but every sentence carries information.

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?

Complete for a mutation tool with no output schema. It closes the gaps an agent would otherwise have: what replaces vs. merges, required preparation (get_campaign), what is immutable (the website), and when changes take effect (future drafts).

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 coverage is 100% so the baseline is 3, but the description adds constraints absent from the schema: array cardinality limits of 20 competitors and 20 audiences. The explicit callout of REPLACE-list behavior is partly redundant with the schema's 'Replaces the list' text, which keeps this from a 5.

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 ('Change') and resource ('the profile every outreach email is written from') and enumerates exactly which fields are editable (niche, competitors, differentiator, audiences), each with an inline gloss. An agent can distinguish this from siblings like set_email_settings or set_link_target 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 explicit operating instructions: 'Pass only the fields to change', 'read get_campaign first and pass the full list with your edits' (naming the sibling to consult), and an exclusion ('The website itself cannot be changed here'). When-to-use and constraints are stated rather than inferred.

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