Get bulletin attachment

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

Without the description an agent would assume this is a pure read, but it discloses the save=true side effect that writes into ~/Downloads/WilmAI — consistent with readOnlyHint=false and idempotentHint=false. It also discloses the dual return shape (file content vs 'not_a_file' plus URL), which is valuable since there is no output schema. Missing is any note on permissions or size/type limits.

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 short sentences, each carrying distinct information: what it fetches, what it returns in each case, and the optional save behavior. Front-loaded and waste-free.

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?

Return-shape disclosure compensates for the absence of an output schema, and the save side effect is covered. Minor gaps: no mention that news_id must be obtained from wilma_list_news/read_news, and no hint about what happens when the attachment cannot be retrieved.

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 75% and the description only restates the save flag already documented in the schema. It adds nothing about news_id (undocumented anywhere) or how student scoping interacts with the fetch, so it does not fully compensate for the coverage gap.

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 ("Fetch a file linked from a bulletin"), with concrete examples of what such files are (PDF letter, menu). It is clearly distinguished from the sibling read tools (wilma_read_news, wilma_list_news) because it retrieves the attachment, not the bulletin text.

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?

Usage is implied by the phrase "so you can read it" and the schema's note that resource_id comes from wilma_read_news, but the description itself never says when to call this instead of wilma_read_news or what to do when the resource is a web page beyond returning 'not_a_file'. No explicit when-not guidance.

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