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

Adds real behavior beyond the annotations: link lifetime (90 days), deterministic output (same events + title always yield the same link, reinforcing idempotentHint), and partial-failure semantics (unknown ids returned as missing). It does not say whether the shareable page is public/private or who can view it, which matters for a sharing tool.

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?

Front-loads the action, count, and artifact before the optional trigger phrases, and packs return/link behavior and failure handling into a short second sentence. The embedded Russian phrase list is dense but purposeful for intent matching.

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?

An output schema exists, yet the description usefully restates the key return (the link) plus its validity window and determinism, and covers the min/max cardinality and missing-id failure mode. Gaps around link visibility/permissions and whether a shortlist can be modified or revoked keep it from a 5.

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 100%, so both parameters are already documented in detail (including the Russian-language/no-emoji title rule and ordering). The description only restates the 2–10 count and that ids come from previous results, adding no format or constraint detail beyond the schema.

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 (Save) plus resource (2–10 events as one shareable page with an explicit URL shape). This is clearly distinguishable from read-oriented siblings get_event, search_events, list_cities, and spontanno_random_event.

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?

Gives concrete triggers («скинь списком», «сохрани», «отправлю друзьям») and situational context (after planning an evening or a weekend), and requires ids from previous results, which implies the search-first workflow. It never names an alternative tool or an explicit when-not-to-use, so it falls short of a 5.

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