Add a symbol to your watchlist (writes to your account)

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

Goes well beyond the annotations by disclosing the default-list fallback including the single-list edge case, dedup behavior ('stays once', consistent with idempotentHint=true), per-connection rate limiting, and account-level auditing of each write. Nothing contradicts the declared hints; the readOnly=false/destructive=false profile is consistent with 'adds' and 'stays once'.

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 tight sentences: trigger first, then resolution/default behavior, then return value and write side effects. Every sentence carries distinct information with no repetition of the title or 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 compensates by stating the return value ('Returns the list's symbols after the change'). Combined with rate-limit and audit side effects and the default-list resolution rules, an agent has everything needed to call this correctly.

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 would be 3, but the description adds real semantics the schema lacks: watchlist_id falls back to the default list and, if the account has only one list, to that list. It also reinforces the symbol-format hint only implicitly, which keeps it from a 5.

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 and resource ('Adds the symbol to the list named by watchlist_id') and pairs it with a natural-language trigger ('watch, follow or add a coin'). It is trivially distinguishable from siblings like remove_watchlist_symbol, list_watchlists, and add_tracked_address without opening the schema.

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 concrete user-intent trigger ('when the user asks to watch, follow or add a coin to their watchlist'), which covers the main selection question. It does not explicitly name the inverse tool (remove_watchlist_symbol) or state when not to use it, so it falls short of full alternative routing.

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