update-file-from-url

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

Annotations already indicate destructive and non-idempotent behavior. Description adds useful context: preserves prior revisions, appears in upload log, replaces only bytes, fallback fetching behavior, and failure condition. No contradictions with annotations, though rate limits or permissions are not mentioned.

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 description is a single paragraph of moderate length. It front-loads the core purpose and includes necessary details without extra fluff. Could be slightly more concise (e.g., breaking fallback behavior into separate sentence), but overall efficient.

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?

Given no output schema, the description mentions return values (file title and URL). It covers prerequisites (file must exist), fallback behavior, and distinguishes from siblings. Error cases are partially covered (failure if file not exists), but could mention invalid URL handling. Still quite complete.

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% with clear descriptions for all 4 parameters. The description does not add significant extra meaning beyond confirming the role of each parameter. Baseline 3 is appropriate as the description adds no additional semantics.

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?

Description starts with a specific verb ('Fetches a file... and uploads it as a new revision of an existing file') and clearly states the resource and action. It differentiates from siblings by explicitly noting when to use update-page for wikitext and upload-file-from-url for initial uploads.

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?

Explicitly states when to use: to update an existing file. Provides alternatives: 'use update-page' for description page edits, 'use upload-file-from-url' for initial upload. Also clarifies that it fails if no file exists, so it's only for updates.

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