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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, so the bar is lower. The description adds genuinely new behavioral context: "No login or account required" (auth requirements) and a disclosure of every result field returned. A small gap is that rate limits, empty-result behavior, and pagination semantics are not addressed, but the added auth and return-content context merit above-baseline credit.

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 information-dense sentences with no filler: purpose with examples, result-field list, and filter/auth notes. The main purpose is front-loaded into the first sentence, and every sentence earns its place.

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?

For a simple, read-only discovery tool with no output schema, the description is nearly complete: it states the resource scope, lists result fields, names all filters, and covers auth. It only lacks finer filter semantics and behavior on empty results, which are minor for a non-destructive query tool.

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 carries the burden. It names all five parameters and labels them as "Filters", which adds grouping semantics, but it doesn't explain their meaning beyond what the self-explanatory names (city, free_only, limit, date_from, date_to) already imply. It does not clarify behaviors like whether date_from defaults to today or what free_only=false means, so compensation for the coverage gap is only partial.

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 opens with a specific verb and resource — "Find public upcoming events on SocialLoop" — and reinforces it with concrete natural-language examples ("what's on in San Francisco this weekend"). The "public upcoming" scope clearly differentiates it from siblings like list_events and list_shared_events, which appear to cover a user's own or shared events.

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?

The example queries establish clear usage context: this is the tool for discovery-style questions about public events. However, it never explicitly names alternatives or states when not to use it (e.g., that list_events exists for a user's own events), so it stops short of full exclusion guidance.

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