One symbol's storylines

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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds substantial behavioral context on top: the default min_topics=2 filter and what an empty list means, the automatic grouping's unreliability, story splitting, and the framing as 'a reading aid, not a count of events'. That caveat materially changes how an agent should trust and present 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?

Dense but front-loaded: purpose first, then the default-filter gotcha, then return shape and caveats. The return-field enumeration is long but earns its place because there is no output schema.

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 no output schema, the description supplies the return fields (name, first_seen, last_seen, topic/statement/mention counts, sources, sentiment, top_topics, related) plus the caveats an agent needs to interpret them. Nothing essential for correct invocation or result interpretation is missing.

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 100%, so the baseline is 3, but the description adds real meaning for min_topics (default hides single-topic storylines; pass 1 to see them), which the schema only states mechanically. Minor deduction for referencing a `topics` parameter that doesn't exist in the schema when explaining top_topics.

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+resource+scope: one company's news grouped into continuing stories (an event plus follow-ups, reactions, consequences). It also distinguishes itself from the sibling get_storyline by naming the case where that tool is needed (every topic in order, or the statements).

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 trigger phrases ('how did the X story unfold', 'what are the ongoing stories about X') and routes to get_storyline for finer detail. It doesn't explicitly exclude other siblings like search_statements or find_topics, so it stops short of a full when/when-not map.

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