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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful behavioral detail beyond the schema: fields are bilingual, every result carries its site URL, and dates are UTC YYYY-MM-DD. That materially informs how the agent interprets results.

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 tight sentences that are front-loaded: what is searched first, then result shape, then the enum semantics that need definition. No redundancy or filler.

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?

With 8 parameters, no required ones, and no output schema, the description carries the return-shape burden well by stating bilingual fields and the presence of a site URL. It could note that no parameters are required and what happens with defaults, but otherwise an agent has enough to call it correctly.

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 most parameters are already documented, so the baseline is 3. The description goes further by defining the status enum values (upcoming/open/ended) and the date semantics, which the schema lists but never explains.

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 gives a specific verb+resource ('Search hackathons') and names the data source (黑123 / hack123.henryht.sh), so the agent knows exactly what is searched. It does not explicitly contrast itself with the sibling get_hackathon, so it falls short of a 5.

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 nature of the tool and the field semantics, but there is no explicit when-to-use / when-not-to-use guidance or a pointer to get_hackathon for single-record lookups. The status definitions help the agent choose a filter, but routing between siblings is left to inference.

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