Save research to my shortlist

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

Annotations already declare the safety profile (idempotent, non-destructive, not read-only), but the description adds context annotations cannot: the OAuth scope requirement (write:shortlist) and reconnection remedy, the fact that existing entries are retained, and the partial-batch failure model with retry guidance. That is exactly the kind of behavioral detail an agent needs before invoking a write 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?

The verb and resource are front-loaded in the first clause, and each subsequent sentence contributes a distinct operational fact (auth, resolution, retention, partial failure, exclusions). There is no filler or repetition of schema-level detail.

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 single-parameter mutation with no output schema, the description covers everything an agent needs: trigger condition, auth prerequisite, input resolution, idempotency/retention semantics, and how failures are surfaced. Nothing material 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% and the schema already documents the tickers array, pattern, and bounds, so the baseline is 3. The description adds real meaning by stressing 'exact Bullrun stock or ETF listing tickers' and by directing the agent to resolve ambiguous names via search_stocks/search_etfs before calling, which prevents the most likely misuse.

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 (Add), resource (exact Bullrun stock or ETF listing tickers), and destination (the signed-in user's Research Shortlist), with the quantity bound (1-20). It also distinguishes itself from siblings by name (search_stocks/search_etfs for resolution, list_research_shortlist implicitly as the read counterpart) and by explicit exclusions (does not create a portfolio, schedule monitoring, or send notifications).

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 a clear trigger ('when the user asks to save them'), an alternative routing rule ('Resolve ambiguous names with search_stocks/search_etfs first'), and explicit exclusions ('Does not create a portfolio, schedule monitoring or send notifications'). Nothing about when to use this versus alternatives 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.