Your watchlists and the symbols on each

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

Beyond readOnlyHint/openWorldHint, it discloses the return shape (id, name, symbol count, plus ordered symbols), the conditional default behavior of include_symbols, the authentication requirement (OAuth sign-in or account key), and the access scope ('reads nothing but this account'). These are exactly the facts an agent cannot get from the annotations.

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 sentences ordered by importance — trigger, return contents, auth/scope — with no filler or repetition of the title.

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 and only one optional parameter, the description supplies everything needed: when to call, what comes back, the flag's effect, and the auth prerequisite.

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?

The single parameter is already 100% documented in the schema, so the baseline is 3; the description adds value by stating the symbols are returned 'unless include_symbols is false' and that they come back 'in order', details absent from 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?

The description pairs a specific verb with a specific resource ('Returns the account's watchlists... and the symbols on each list') and states the triggering user intents, so it is distinguishable from the many market-data 'get_*' siblings at a glance.

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?

It gives concrete use conditions: user asks what is on a watchlist, which lists exist, or as a prerequisite 'before adding or removing a symbol' — which implicitly routes to add_watchlist_symbol/remove_watchlist_symbol. The alternative tools are not named explicitly and there are no exclusion statements, 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.