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

Annotations already flag destructiveHint=true, but the description adds concrete consequences beyond them: voice/key_facts/rules wholesale replacement, 'remove_author' falling back to the brand's byline, and images fields 'left out stay' (partial-update semantics). The mandatory read-first instruction further mitigates the destructive profile. This is substantive behavioral context the annotations cannot express.

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 destructive-replacement warning and the read-first instruction are front-loaded, then a compact per-action bullet list follows, each bullet pairing an action with its parameters. Almost no sentence is wasted, though the first sentence packs three ideas (ownership, settings location, replacement semantics) into one dense line.

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 12-parameter destructive mutation with no output schema, the definition covers the prerequisites, the per-action parameter mapping, and the consequences of each action, which is what an agent needs to call it correctly. It does not state what the call returns or whether an invalid action/parameter combination is rejected, and the implicit rule that only parameters relevant to the chosen action take effect is left to 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?

With 0% schema description coverage across 12 parameters, the description carries the full burden and does: every parameter is mapped to an action (author→name/credentials/sameAs, voice→text, key_facts→keyFacts, rules→add/replace, images→screenshots/brandColor/cardBackground/font). It also disambiguates the pair most likely to be confused, 'add one line, or replace them all', and constrains sameAs to 'up to 6 https profiles', which the schema enumerates only as maxItems.

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?

The description names a specific resource, the brand's writing rules (Settings → Writing, Images), and enumerates the six sub-resources it changes via the action enum (author, voice, key_facts, rules, images). An agent can tell this apart from update_brand or update_page, though the opening sentence ('The brand's rules for whoever writes, Sightkick or you') is idiosyncratically phrased and never uses a plain verb like 'updates'.

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 gives an explicit prerequisite: 'read get_settings writing first', naming the sibling tool to call before mutating. It also warns that voice, key_facts and rules replace the whole text, which steers toward read-before-write. It stops short of stating when not to use this tool (e.g., per-page overrides belong to update_page).

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