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

The annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered and the bar is lower. The description usefully discloses that the response aggregates several secondary collections (official sources, related works, active team posts), which hints at payload size and joins, but says nothing about caching, rate limits, or error behavior for an invalid slug.

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?

A single sentence that front-loads the verb and resource, then embeds the parameter explanation parenthetically and closes with the return contents. Zero filler and no repetition of the title.

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?

There is no output schema, so the description correctly compensates by naming what comes back. Combined with the annotations covering the read-only profile, an agent has enough to call this correctly; only edge cases (unknown slug, pagination of team posts) are unaddressed.

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 parameter burden, and it does: it defines slug as 'the part after /h/ in the site URL', which is exactly the disambiguation an agent needs to construct a valid value. It adds no format constraints (case sensitivity, length) but the semantic meaning is delivered.

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 ('Get one hackathon by slug') and immediately scopes it against the sibling search tools by acknowledging it fetches a single entity by identifier. It also enumerates the payload (bilingual details, official sources, related works, active team posts), so an agent can distinguish it from search_hackathons 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?

Usage is implied rather than stated: the slug parameter tells the agent this is a single-record lookup, and the existing slug is the entry condition. However, no siblings are named as alternatives (e.g. 'use search_hackathons if you only have a name'), and there is 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.